#!/usr/bin/env python3
#
# Copyright (C) 2023-2024 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# T5160: Firewall re-writing

#  cli changes from:
#  set firewall name <name> ...
#  set firewall ipv6-name <name> ...
#  To
#  set firewall ipv4 name <name>
#  set firewall ipv6 name <name>

## Also from 'firewall interface' removed.
## in and out:
    # set firewall interface <iface> [in|out] [name | ipv6-name] <name>
    # To
    # set firewall [ipv4 | ipv6] forward filter rule <5,10,15,...> [inbound-interface | outboubd-interface] interface-name <iface>
    # set firewall [ipv4 | ipv6] forward filter rule <5,10,15,...> action jump
    # set firewall [ipv4 | ipv6] forward filter rule <5,10,15,...> jump-target <name>
## local:
    # set firewall interface <iface> local [name | ipv6-name] <name>
    # To
    # set firewall [ipv4 | ipv6] input filter rule <5,10,15,...> inbound-interface interface-name <iface>
    # set firewall [ipv4 | ipv6] input filter rule <5,10,15,...> action jump
    # set firewall [ipv4 | ipv6] input filter rule <5,10,15,...> jump-target <name>

from sys import argv
from sys import exit

from vyos.configtree import ConfigTree

if len(argv) < 2:
    print("Must specify file name!")
    exit(1)

file_name = argv[1]

with open(file_name, 'r') as f:
    config_file = f.read()

base = ['firewall']
config = ConfigTree(config_file)

if not config.exists(base):
    # Nothing to do
    exit(0)

### Migration of state policies
if config.exists(base + ['state-policy']):
    for state in config.list_nodes(base + ['state-policy']):
        action = config.return_value(base + ['state-policy', state, 'action'])
        config.set(base + ['global-options', 'state-policy', state, 'action'], value=action)
        if config.exists(base + ['state-policy', state, 'log']):
            config.set(base + ['global-options', 'state-policy', state, 'log'], value='enable')
    config.delete(base + ['state-policy'])

## migration of global options:
for option in ['all-ping', 'broadcast-ping', 'config-trap', 'ip-src-route', 'ipv6-receive-redirects', 'ipv6-src-route', 'log-martians',
                'receive-redirects', 'resolver-cache', 'resolver-internal', 'send-redirects', 'source-validation', 'syn-cookies', 'twa-hazards-protection']:
    if config.exists(base + [option]):
        if option != 'config-trap':
            val = config.return_value(base + [option])
            config.set(base + ['global-options', option], value=val)
        config.delete(base + [option])

### Migration of firewall name and ipv6-name
### Also migrate legacy 'accept' behaviour
if config.exists(base + ['name']):
    config.set(['firewall', 'ipv4', 'name'])
    config.set_tag(['firewall', 'ipv4', 'name'])

    for ipv4name in config.list_nodes(base + ['name']):
        config.copy(base + ['name', ipv4name], base + ['ipv4', 'name', ipv4name])

        if config.exists(base + ['ipv4', 'name', ipv4name, 'default-action']):
            action = config.return_value(base + ['ipv4', 'name', ipv4name, 'default-action'])

            if action == 'accept':
                config.set(base + ['ipv4', 'name', ipv4name, 'default-action'], value='return')

        if config.exists(base + ['ipv4', 'name', ipv4name, 'rule']):
            for rule_id in config.list_nodes(base + ['ipv4', 'name', ipv4name, 'rule']):
                action = config.return_value(base + ['ipv4', 'name', ipv4name, 'rule', rule_id, 'action'])

                if action == 'accept':
                    config.set(base + ['ipv4', 'name', ipv4name, 'rule', rule_id, 'action'], value='return')

    config.delete(base + ['name'])

if config.exists(base + ['ipv6-name']):
    config.set(['firewall', 'ipv6', 'name'])
    config.set_tag(['firewall', 'ipv6', 'name'])

    for ipv6name in config.list_nodes(base + ['ipv6-name']):
        config.copy(base + ['ipv6-name', ipv6name], base + ['ipv6', 'name', ipv6name])

        if config.exists(base + ['ipv6', 'name', ipv6name, 'default-action']):
            action = config.return_value(base + ['ipv6', 'name', ipv6name, 'default-action'])

            if action == 'accept':
                config.set(base + ['ipv6', 'name', ipv6name, 'default-action'], value='return')

        if config.exists(base + ['ipv6', 'name', ipv6name, 'rule']):
            for rule_id in config.list_nodes(base + ['ipv6', 'name', ipv6name, 'rule']):
                action = config.return_value(base + ['ipv6', 'name', ipv6name, 'rule', rule_id, 'action'])

                if action == 'accept':
                    config.set(base + ['ipv6', 'name', ipv6name, 'rule', rule_id, 'action'], value='return')

    config.delete(base + ['ipv6-name'])

### Migration of firewall interface
if config.exists(base + ['interface']):
    fwd_ipv4_rule = 5
    inp_ipv4_rule = 5
    fwd_ipv6_rule = 5
    inp_ipv6_rule = 5
    for direction in ['in', 'out', 'local']:
        for iface in config.list_nodes(base + ['interface']):
            if config.exists(base + ['interface', iface, direction]):
                if config.exists(base + ['interface', iface, direction, 'name']):
                    target = config.return_value(base + ['interface', iface, direction, 'name'])
                    if direction == 'in':
                        # Add default-action== accept for compatibility reasons:
                        config.set(base + ['ipv4', 'forward', 'filter', 'default-action'], value='accept')
                        new_base = base + ['ipv4', 'forward', 'filter', 'rule']
                        config.set(new_base)
                        config.set_tag(new_base)
                        config.set(new_base + [fwd_ipv4_rule, 'inbound-interface', 'interface-name'], value=iface)
                        config.set(new_base + [fwd_ipv4_rule, 'action'], value='jump')
                        config.set(new_base + [fwd_ipv4_rule, 'jump-target'], value=target)
                        fwd_ipv4_rule = fwd_ipv4_rule + 5
                    elif direction == 'out':
                        # Add default-action== accept for compatibility reasons:
                        config.set(base + ['ipv4', 'forward', 'filter', 'default-action'], value='accept')
                        new_base = base + ['ipv4', 'forward', 'filter', 'rule']
                        config.set(new_base)
                        config.set_tag(new_base)
                        config.set(new_base + [fwd_ipv4_rule, 'outbound-interface', 'interface-name'], value=iface)
                        config.set(new_base + [fwd_ipv4_rule, 'action'], value='jump')
                        config.set(new_base + [fwd_ipv4_rule, 'jump-target'], value=target)
                        fwd_ipv4_rule = fwd_ipv4_rule + 5
                    else:
                        # Add default-action== accept for compatibility reasons:
                        config.set(base + ['ipv4', 'input', 'filter', 'default-action'], value='accept')
                        new_base = base + ['ipv4', 'input', 'filter', 'rule']
                        config.set(new_base)
                        config.set_tag(new_base)
                        config.set(new_base + [inp_ipv4_rule, 'inbound-interface', 'interface-name'], value=iface)
                        config.set(new_base + [inp_ipv4_rule, 'action'], value='jump')
                        config.set(new_base + [inp_ipv4_rule, 'jump-target'], value=target)
                        inp_ipv4_rule = inp_ipv4_rule + 5

                if config.exists(base + ['interface', iface, direction, 'ipv6-name']):
                    target = config.return_value(base + ['interface', iface, direction, 'ipv6-name'])
                    if direction == 'in':
                        # Add default-action== accept for compatibility reasons:
                        config.set(base + ['ipv6', 'forward', 'filter', 'default-action'], value='accept')
                        new_base = base + ['ipv6', 'forward', 'filter', 'rule']
                        config.set(new_base)
                        config.set_tag(new_base)
                        config.set(new_base + [fwd_ipv6_rule, 'inbound-interface', 'interface-name'], value=iface)
                        config.set(new_base + [fwd_ipv6_rule, 'action'], value='jump')
                        config.set(new_base + [fwd_ipv6_rule, 'jump-target'], value=target)
                        fwd_ipv6_rule = fwd_ipv6_rule + 5
                    elif direction == 'out':
                        # Add default-action== accept for compatibility reasons:
                        config.set(base + ['ipv6', 'forward', 'filter', 'default-action'], value='accept')
                        new_base = base + ['ipv6', 'forward', 'filter', 'rule']
                        config.set(new_base)
                        config.set_tag(new_base)
                        config.set(new_base + [fwd_ipv6_rule, 'outbound-interface', 'interface-name'], value=iface)
                        config.set(new_base + [fwd_ipv6_rule, 'action'], value='jump')
                        config.set(new_base + [fwd_ipv6_rule, 'jump-target'], value=target)
                        fwd_ipv6_rule = fwd_ipv6_rule + 5
                    else:
                        new_base = base + ['ipv6', 'input', 'filter', 'rule']
                        # Add default-action== accept for compatibility reasons:
                        config.set(base + ['ipv6', 'input', 'filter', 'default-action'], value='accept')
                        config.set(new_base)
                        config.set_tag(new_base)
                        config.set(new_base + [inp_ipv6_rule, 'inbound-interface', 'interface-name'], value=iface)
                        config.set(new_base + [inp_ipv6_rule, 'action'], value='jump')
                        config.set(new_base + [inp_ipv6_rule, 'jump-target'], value=target)
                        inp_ipv6_rule = inp_ipv6_rule + 5

    config.delete(base + ['interface'])

try:
    with open(file_name, 'w') as f:
        f.write(config.to_string())
except OSError as e:
    print("Failed to save the modified config: {}".format(e))
    exit(1)
